Index: llvm/trunk/include/llvm/Support/JSON.h
===================================================================
--- llvm/trunk/include/llvm/Support/JSON.h
+++ llvm/trunk/include/llvm/Support/JSON.h
@@ -294,9 +294,13 @@
   Value(json::Array &&Elements) : Type(T_Array) {
     create<json::Array>(std::move(Elements));
   }
+  template <typename Elt>
+  Value(const std::vector<Elt> &C) : Value(json::Array(C)) {}
   Value(json::Object &&Properties) : Type(T_Object) {
     create<json::Object>(std::move(Properties));
   }
+  template <typename Elt>
+  Value(const std::map<std::string, Elt> &C) : Value(json::Object(C)) {}
   // Strings: types with value semantics. Must be valid UTF-8.
   Value(std::string V) : Type(T_String) {
     if (LLVM_UNLIKELY(!isUTF8(V))) {
Index: llvm/trunk/unittests/Support/JSONTest.cpp
===================================================================
--- llvm/trunk/unittests/Support/JSONTest.cpp
+++ llvm/trunk/unittests/Support/JSONTest.cpp
@@ -47,6 +47,8 @@
             s(Object{{"A", Object{{"B", Object{{"X", "Y"}}}}}}));
   EXPECT_EQ("null", s(llvm::Optional<double>()));
   EXPECT_EQ("2.5", s(llvm::Optional<double>(2.5)));
+  EXPECT_EQ("[[2.5,null]]", s(std::vector<std::vector<llvm::Optional<double>>>{
+                                 {2.5, llvm::None}}));
 }
 
 TEST(JSONTest, StringOwnership) {